Lobster wrote:
Nick Brooks wrote in message ...


I'd like to replace the water main to the house. The water company have
asked for a trench 750mm deep lined with pea-gravel or similar do be dug
from teh house to the road.

The biggest problem is that the trench will have to go through/under the
garden wall which is a 120 year old dry stone construction which may
well not cope well.

However , when a gas supply was installed, Transo used some sort of
tunneling device to connect two small holes. I wasn't at home at the
time so didn't see the operation, but a now wondering if a similar
machine could be used to bore a tunnel for the water pipe.

Can these machines be hired or does one have to get a specialist in?


To the first question, yes definitely; and to the second, yes IMHO!

See http://tinyurl.com/23se9 or
http://www.hss.com/Fae.asp?sysPage=w...sysLanguag e=[BASE]&resetToGroup=YES

I recently watched with fascination as United Utilities used one of
these to install a water pipe under the pavement near me. They had
this mole, a metal cylinder about 3" by 2', connected to a compressor
via a hose; shoved it down a hole and let it rip. Off it went down
the road, beneath the pavement, until it emerged in another pit about
10' away. Having done it's job, the bloke yanked it back by the hose
and tossed it on the pavement, where it sat thrashing about like a
demented eel till the air ran out.

God knows how they control its direction and gradient; and presumably
they'd already checked for any stray service pipes in harm's way. I
certainly wouldn't fancy trying to use it in anger myself.

During the same job (above) I had to get a water pipe from the inside
of my property to the outside, 750mm below the surface, which is
pretty much what you're doing... is your wall at the boundary, or will
you be able to dig down at both sides of the wall and meet in the
middle underneath? If so, that shouldn't be much bother. If you're
at the boundary, the water co will insist you break right through the
foundations of the wall from your side only (you're absolutely not
allowed to dig up the pavement yourself!), then will probably send a
jobsworth inspector round to ensure you've done precisely that before
they will dig up the pavement themselves (although the job would be
infinitely easier working from both sides). I expect this is where
you're coming from, right?!!

I'm guessing the drystone wall won't have foundations as deep as
750mm; and if it does, it will only be rubble-type stuff (my 100-year
old house wall was, anyway!). I got through eventually using a
combination of a lump hammer, builder's chisel, pointing trowel(!) and
a length of 1.25" plastic waste pipe, used as a coring tool. Sod of a
job - good luck!

David

You've described my situation exactly. The man from the water cpmpany is
coming today. I'll let you know what happens

NB